This invention relates to improvements in fasteners, in particular to improvements in shearable fasteners. Such fasteners are particularly suitable for securing electrical conductors to electrical connectors.
Electrical connectors are widely used for the jointing of two or more electrical cables or conductors. One form of such connector comprises a body with blind bores into which the ends of the conductors are inserted. Each conductor is fixed in place by threaded fasteners which are engaged with threaded bores in the wall of the blind bore and which hold the conductor against the opposite internal face of the bore. Commonly, Such fasteners have shearable heads which break off at a certain predetermined applied torque. This prevents excessive and possibly damaging, force being applied to the conductor and also results in the assembled joint having a reasonably smooth profile.
Known systems of the type described above suffer from the disadvantage, however that because the conductors joined together using the connector may take various different sizes it is necessary for the shearable fasteners to be produced in a corresponding range of lengths in order to ensure that the assembled joint has the desired smooth profile. This means that a fitter must carry a suitable supply of all different sizes and can result in mistakes being made and inappropriate fasteners being used.
British Patent Application No GB 2281599 describes a threaded fastener which, when applied using a special tool, is arranged to shear at an axial position along its length corresponding to the surface of an electrical connector with which it is engaged. However, such a fastener can only be used in conjunction with such a special tool.
There has now been devised an improved fastener, of particular use in securing an electrical conductor to an electrical connector, which overcomes or substantially mitigates the above mentioned disadvantage.